Process for the manufacture of threads or films of cellulose.



- 'UNITED 1 STATES PATENT OFFICE.

MAX FREMERY, OF OBERBRUOK, AND EMILE BEONNERT. OF MI'iLHAU- SEN-NIEDERMORSCHWEILER, GERMANY, AND 'JOHANN URBAN, or sT. POLTEN, AUSTRIA-HUNGARY. i

PROCESS FORTHE MANUFACTURE OF THREADS OR FILMS OF- CELLULOSE.

To all whom it may concern:

ing at Oberbruck, Province of the Rhine, and

EMILE BRONNERT, residing at *Mulhausenlulose, such as dilute acetic acid, winding the wet thread thus produced onto a roller revolving in a bath of dilute acid, such as acetic acid, and after washing away the ammonia and copper drying under tension.

The economical valueof the process above described resides in the fact that both the ammonia and copper can be recovered from the acid solution. When, however, the process is used for making threads of considerable thickness or for making films, for which purpose large capillary tubes or slitshaped openings must be used for the injectin apparatus, the threads obtained are so dlfil and inelastic that they are practically useless and the films are not transparent and are brittle and inelastic. 4

By the present invention the cellulose solution is in'ected'into an acid, preferably sulfuric aci of thirty to sixty-five per cent.

strength, as described in United States Patent Specification No. 698,254, whereby the advantage of recovering the copper and am.

monia is retained, but the threads or films produced are treated with a strong causticalkali solutionfor instance, a cold solution containing not less than twenty per cent. of

Q Specification of Letters Patent. Application filed May 8,1905. Serial No. 259A'79.

I I caustic soda. 1 Be it known that we, MAX FREMERY, resid V Patented. Dec. .5, 1905.

.For this purpose the threads or films as'they are produced may be wound on a cylinder, which is then rotated for some time in a bath of cold strong caustic-alkali solution, or the threads or films may be placed in the perforated drum of a centrifugal ap aratus and the cold strong caustic-alkali so ution may be introduced under pressure through'the axle of the drum. In either case the treatment is followed by washing with water, preferably in the manner de- .7

scribed United States Patent Sp ecifica tions 'Nos. 661,214jand 705,748, until all caustic soda has been washed from them, and

finally with watercontaining a small proportionof a dilute acid,- like acetic acid. The I threads or films are then driedunder tension,

. as described in United States Patent Specifications No's. 650,715 and 691,257.

1 The films and thick threads made accord? ing to this invention are as transparent as glass, very strong, and about twice as elastic as those-produced by the older processes.

Having thus described the nature of. this invention and the best means "we know of carrying the sameinto practical effect, we claim 1. A process for the manufacture of threads or films of cellulose consisting ininj ecting into an acid a cupriferous ammoniacal solution of .cellulose' and then treating the cellulose form thus produced with a strong solution of caustic alkali.

2. A process for the manufacture of threads or films of cellulose consisting in injecting intoan acid a cupriferous ammoniacal solution of cellulose and then treating the cellulose form thus produced with a strong solution of caustic alkali and finally washin the form with water and a dilute acid an dryingit under tension.

3. A process for the manufacture of threads or films of cellulose consisting in injecting into an acid a cupriferous ammoniacal solution of cellulose and winding up the cellu .Which rotates in a strong solution of caustic alkali, then Washing the form With water and a dilute acid, and drying it under tension.

5. Threads or films of cellulose prepared by injecting into an acid a cupriferous ammoniacal solution of cellulose and treating the cellulose form thus produced With a strong solution of caustic soda.

In testimony whereof We have signed our names to this specification in the presence of subscribing Witnesses.

I MAX FREMERY.

EMILE BRONNERT. JOHANN URBAN.

Witnesses to the signature of Max Fremery:

HENRY QUADRLUG, GERARD OELLERS.

Witnesses to the signature of Emile Bronnert:

ALBERT GRAETER, Gno. GIFFORD.

Witnesses to the signature of Johann U rban:

ALvEsTo S. HoGUE, AUGUST FUGGER. 

